The Coast Survey Development Laboratory (CSDL) has developed techniques and software to create a digital, geo-referenced coastal map raster data layer. The data layer will be derived directly from the NOS nautical chart and contain the hydrography, topography and shoreline base information. Each coastal map data layer will be offered as a single GEOTIFF file for ease of transfer and use by the coastal stewardship community. Additionally, users can disseminate the coastal map files along with their data to their constituents.

Purpose:

There has been an increasing demand from the coastal stewardship community and the general public for non-proprietary version of the NOS nautical chart images to use as backdrops to Geographic Information System (GIS) derived products. Utilizing their own data, GIS users will be able to overlay the coastal map layer to create new views of their data necessary for advanced analysis and presentation.

Supplemental_Information:

The data is intended for use as an imagery backdrop to represent the charted hydrography and topography of a given area. It is in no way intended for navigational uses. The data accuracy is checked against its source nautical chart only. NOAA assumes no liability for use of this data.

Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date: 200110

Ending_Date: 200405

Currentness_Reference: publication date

Status:

Progress: In work

Maintenance_and_Update_Frequency: As needed

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate: 178

East_Bounding_Coordinate: -50.3

North_Bounding_Coordinate: 81.9

South_Bounding_Coordinate: -14.6

Keywords:

Theme:

Theme_Keyword_Thesaurus: none

Theme_Keyword: Coastal Maps

Theme_Keyword: Geographic Information Systems

Theme_Keyword: Hydrography

Theme_Keyword: Topography

Theme_Keyword: GEOTIFF

Theme_Keyword: Shoreline

Theme_Keyword: Base Layer

Theme_Keyword: Nautical Charts

Theme_Keyword: marine navigation

Theme_Keyword: oceans

Theme_Keyword: coastal management

Place:

Place_Keyword_Thesaurus: none

Place_Keyword: U.S. Exclusive Economic Zone

Place_Keyword: U.S. Territories

Place_Keyword: U.S. Waters

Place_Keyword: EEZ

Access_Constraints: none

Use_Constraints:

The data is intended for use as an imagery backdrop to represent the charted hydrography and topography of a given area. It is in no way intended for navigational uses. The data accuracy is checked against its source nautical chart only. NOAA assumes no liability for use of this data.

The data accuracy is checked against its source nautical chart only. Nautical charts are verified and updated as part of an ongoing process to create a cartographic representation of the best available data collected through the years employing a variety of collection techniques and provided to the Office of Coast Survey using numerous different data types, scales, datums, and projections. Prior to 1995, the paper charts were composed manually. In 1995, the paper charts were scanned to create the raster charts. Both the paper and raster charts are composed from the same digital files. The data accuracy is checked against its source nautical chart only. NOAA assumes no liability for use of this data.

Logical_Consistency_Report: Observations are consistent throughout this raster data set.

Completeness_Report:

The NOAA Nautical Chart Manual Seventh (1992) Edition contains a complete list of selection criteria, generalization, and definitions that were used to determine what is included in the data set. Charting material consists principally of topographic and hydrographic surveys made by NOS supplemented by miscellaneous surveys and textual information provided by other organizations. All material must be critically examined, with particular attention directed to the actual date of the survey, geographic datum, depth unit, plane of reference, purpose and quality of the survey, and whether it is an original source or from another compilation. A partial listing of sources of cartographic data follows: U.S. Army Corps of Engineers, U.S. Coast Guard, National Imagery and Mapping Agency, NOAA Office of Coast Survey/National Ocean Service, U.S. Geological Survey, St. Lawrence Seaway Development Corp, Environmental Protection Agency, U.S. National Park Service, State Department, NOAA National Weather Service, NOAA National Marine Fisheries, National Archives, NOAA National Environmental Satellite Data and Information Service, state and local sources, private sources, and international sources.

Positional_Accuracy:

Horizontal_Positional_Accuracy:

Horizontal_Positional_Accuracy_Report:

Nautical charts are updated as part of an ongoing process to create a cartographic representation of the best available data collected through the years employing a variety of data collection technology and techniques and provided to the Office of Coast Survey using numerous different scales, datums, and projections. Technology has allowed for a drastic increase in positional accuracy. However, historical data has not been superseded in many areas. The availability of digital chart products and Differential Global Positioning System (DGPS) has drastically changed navigation. Navigation systems using DGPS for locating a vessel's position on the earth have put mariners in a unique predicament due to a false perception of greater positional accuracy of features portrayed on the charts. In many cases, the DGPS is more accurate than the surveying technology that was used to put the soundings and features on the nautical chart, paper or raster. The data accuracy is checked against its source nautical chart only. NOAA assumes no liability for use of this data.

Vertical_Positional_Accuracy:

Vertical_Positional_Accuracy_Report:

Depths are biased for shoals. Charts use multiple vertical datums (Mean Higher High Water [MHHW]; Mean High Water [MHW]; Mean Sea Level [MSL]; Mean Low Water [MLW]; Low Water Datum [LWD]; Mean Lower Low Water [MLLW]; Gulf Coast Low Water Datum [GCLWD].) The NOAA Nautical chart manual has an extensive description of the vertical datum used. Sounding datums used in coastal areas for nautical charting are determined by local observations, ideally over a period of 19 years. The official time period over which tide observations are taken to obtain mean values for tidal datums has been standardized by NOS. The present National Tidal Datum Epoch is from 1960 through 1978. There have been two epochs used previously this century; 1924 through 1942, and 1941 through 1959. The individual chart title block documents the datum used for that chart. Nautical charts are updated as part of an ongoing process to create a cartographic representation of the best available data collected through the years employing a variety of data collection technology and techniques. As technology has allowed for a drastic increase in survey accuracy historical data has not been superseded for many areas. Therefore, soundings found on a single chart may contain multiple collection dates and be only accurate as the technology used to collect them allowed. The data accuracy is checked against its source nautical chart only. NOAA assumes no liability for use of this data.

Lineage:

Source_Information:

Source_Citation:

Citation_Information:

Originator: NOAA, NOS, OCS, Marine Charting Division

Publication_Date: 19950101

Title: Nautical Charts

Geospatial_Data_Presentation_Form: raster digital data

Series_Information:

Series_Name: NOAA Nautical Charts

Issue_Identification: kapp number

Publication_Information:

Publication_Place: Silver Spring, MD

Publisher: NOAA's Ocean Service, Office of Coast Survey

Source_Scale_Denominator: 10,000 to 80,000

Type_of_Source_Media: Raster Images

Source_Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date: 19950101

Ending_Date: present

Source_Currentness_Reference: publication date

Source_Citation_Abbreviation: Source Nautical Chart

Source_Contribution:

All information in Coastal Maps is derived from the Source Nautical Chart.

Process_Step:

Process_Description:

The processing technique associated with coastal map production is quite simple. First, each binary separate raster plate (Intergraph CIT) is opened using the standard raster nautical chart production software (MicroStation/IRASB). A cartographer "cleans" the plates by removing all navigational and other additional information that is not native to the coastal map series. All the cleaned binary raster files for a given chart are then combined and converted to a packbits compressed TIFF format that is about 5MB. A corresponding world file is created using software developed by Cartographic & Geospatial Technology Program (CGTP) and ArcView 8 on a NT 4.0 operating system. The TIFF has emerged as one of the world's most popular raster file formats but has limitations in cartographic applications, since it does not have the structure for conveying geographic information. Several proprietary solutions exist for recording geographic information in TIFF tags. Intergraph Corporation has a geotie tag implementation, but this remains within the private TIFF tagset registered exclusively to Intergraph. Other companies (such as ESRI, MapTech, and Island Graphics) have geographic solutions that are also proprietary or limited by specific application to their software's architecture. Many GIS companies, raster data providers, and clients demand that the companies concerned with delivery and exploitation of raster geographic imagery work with a publicly available, platform interoperable standard for the support of geographic TIFF imagery. Coastal Map GEOTIFF images are supported by a world file that is able to be read and positioned correctly in any GIS or digital mapping system, which supports the "GEOTIFF" standard. The savings to the users and providers of raster data and software are significant. With a platform interoperable coastal map, companies will not have to develop resources in support of proprietary formats. NOAA will be able to produce off-the-shelf imagery products, which can be delivered in the "generic" TIFF format quickly and at low cost. End-users will have the advantage of developed software that exploits the GEOTIFF tags transparently. Most importantly, the same raster GEOTIFF image which can be read and modified in one GIS environment may be equally exploitable in another GIS environment without requiring any file duplication or import/export operation.

A hydrographic chart is a nautical chart showing depths of water, nature of bottom, contours of bottom and coastline, and tides and currents in a given sea or sea and land area. Charted depths are the vertical distance from the tidal datum to the bottom. The bottom type is the feature of the bottom including the material of which it is composed and its physical characteristics. Bottom contours are lines joining points of equal vertical distance above or below a datum. Finally, coastline is a line of ordinary low water along that portion of the coast which is in direct contact with the open sea and the line marking the seaward limit of inland waters.

The data is intended for use as an imagery backdrop to represent the charted hydrography and topography of a given area. It is not intended for navigational uses. The data accuracy is checked against its source nautical chart only. NOAA assumes no liability for use of this data.